Pressure induced surface wetting for enhanced spreading and controlled filament size

A roller includes a cylindrical outer surface of a hydrophobic material, an inner core of a hydrophilic material, and an inhomogeneous geometric pattern of grooves in the surface that expose the hydrophilic material. A method of manufacturing a roller, includes providing a cylindrical core of a hydrophilic material, covering the cylindrical core with a hydrophobic surface, creating grooves in the hydrophobic surface to form a geometrically inhomogeneous pattern of the hydrophilic material. A method of manufacturing a roller, includes forming a pattern of geometrically inhomogeneous grooves on a hydrophobic core, functionalizing the surface to make the surface hydrophilic, and removing a portion of a top layer of the hydrophobic core to expose the hydrophobic core, leaving hydrophilic grooves.

Skip to: Description  ·  Claims  ·  References Cited  · Patent History  ·  Patent History
Description
RELATED APPLICATIONS

This application is related to the following US applications and patents:

US Patent Publication No. US2015011947, “Method of Creating an Aerosol by Stretching Filaments Between Two Diverging Surfaces,”;

US Patent Publication No. US20150343477, “System for Creating Aerosols by Stretching Filaments,”;

US Patent Publication No. US20150115057, “System for Creating Aerosols by Stretching Filaments,”;

US Patent Publication No. US20150210009, “Spray Deposition System,”;

US Patent Publication No. US20150343468, “System for Creating Aerosols by Stretching Filaments,”;

U.S. Pat. No. 9,257,056, “System for Creating Aerosols by Stretching Filaments,”;

US Patent Publication No. 20160175856, “Spray Deposition System,”;

U.S. patent application Ser. No. 14/575,922, “System for Creating Aerosols by Stretching Filaments,”;

U.S. patent application Ser. No. 15/001,408, “System Using Aerosol Generation and Selective Charging,”;

U.S. patent application Ser. No. 15/001,452, “Method Using Aerosol Generation and Selective Charging,”; and

U.S. patent application Ser. No. 15/651,195, “Central Fed Roller for Filament Extension Atomizer,”.

TECHNICAL FIELD

This disclosure relates to filament extension atomizer systems, more particularly to rollers used in these systems.

BACKGROUND

Palo Alto Research Center, Inc. (“PARC”) has developed a filament extension atomizer system that generates aerosols from liquids. The system generally involves stretching a liquid filament between two diverging surfaces until the filament breaks up into a spray of droplets. In some versions of the system, the fluid input to the system involves doctor blades and the pressure formed between the two surfaces. In one version, the two surfaces are rollers and the rollers form a nip between them to distribute the fluid.

Typically, for most fluids this is very effective. However, for fluids with relatively high surface tension, and therefore having large contact angles on a flat and smooth surface, spreading the fluid uniformly in a controlled manner on rapidly moving surfaces becomes problematic. The spreading can typically be enhanced by using more hydrophilic materials, such as plastics with polar monomers or metal oxides, which lower the contact angle. Although even this approach often fails to generate ideal surface wetting for generating a consistent spray from high surface tension fluids.

SUMMARY

An embodiment consists of a roller including a cylindrical outer surface of a hydrophobic material, an inner core of a hydrophilic material, and an inhomogeneous geometric pattern of grooves in the surface that expose the hydrophilic material.

An embodiment consists of a method of manufacturing a roller including providing a cylindrical core of a hydrophilic material, covering the cylindrical core with a hydrophobic surface, creating grooves in the hydrophobic surface to form a geometrically inhomogeneous pattern of the hydrophilic material.

An embodiment consists of a method of manufacturing a roller including forming a pattern of geometrically inhomogeneous grooves on a hydrophobic core, functionalizing the surface to make the surface hydrophilic, and removing a portion of a top layer of the hydrophobic core to expose the hydrophobic core, leaving hydrophilic grooves.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of radii involved in the development of a roller.

FIG. 2 shows an embodiment of a filament extension atomizer system.

FIG. 3 shows an embodiment of a pair of counter rotating rollers in which one is a roller with a helical groove.

FIG. 4 shows a diagram of a grooved roller.

FIG. 5-7 show different embodiments of grooved rollers.

FIGS. 8-9 show surface profile measurements for different roller embodiments.

 DETAILED DESCRIPTION OF THE EMBODIMENTS

As mentioned previously, issues arise with higher surface tension liquids because they do not spread easily over most commercially available machinable materials, such as metals and thermoplastics. High surface tension fluids, particularly surfactant-free aqueous mixtures, tend to coalesce rather than spread and the contact angles of these fluids may surpass 90°. Thus, manipulating the film thickness becomes increasingly difficult as surface tension increases. Applying pressure to the surface of the roller with a doctoring blade results in fluid being trapped between the roller and blade, and eventually being expelled to the sides. When the interaction energy between the fluid and surface is favorable, film thickness is modified by altering the flow rate from the feed with the doctoring blade in contact. The fluid adheres to roller surface and can pass through the doctoring blade because of the lower contact angle.

The use of high surface energy plastic rollers provides lower contact angles, but is often insufficient to spread the fluid with a doctor blade. Embodiments here rely on capillary pressure by using patterned grooves on the surface, which generates strong fluid adhesion in discrete, hydrophilic, regions of the roller. Varying the groove dimensions also allows control of the filament size which will ultimately affect the size of the droplets in the spray. The fluids can be strictly confined to the grooves by coating the ridges with a hydrophobic material, and having them separated by ridges less than three times the size of the grooves. This effectively narrows the droplet size distribution by generating filaments in discrete sizes.

These rollers are fabricated by using a hydrophilic core such as polyetherimide, and in some embodiments may involve coating it with a hydrophobic material such as PTFE, Teflon, etc., only a few microns thick. The channels are then created using a turn finish of a desired radius, Ra, depending on desired filament size. The capillary pressure in the channels spontaneously draws fluid into them, while the hydrophobic ridges repel fluid into the hydrophilic channels. The capillary pressure is calculated using the Laplace equation:

Δ ⁢ ⁢ P = σ ⁡ ( 1 R 1 + 1 R 2 )
where R1 and R2 are the radii of curvature of the surface and σ is the surface tension.

R 1 = R m = R cos ⁡ ( θ + ϑ ) .
Rm is substituted for R1 which is shown in FIG. 1. The angle θ is the contact angle of the fluid on the surface, and ϑ is the angle bisecting the capillary. For situations where R2>>R1, the term 1/R2 is omitted, which gives rise to:

Δ ⁢ ⁢ P = cos ⁡ ( θ + ϑ ) R

FIG. 2 shows a filament extension atomizer system. Two counter rotating rollers 100 and 102 stretch a fluid 106 that flows through the nip 104. The nip 104 is the space between the two rollers 100, 102 into which the fluid is drawn when the rollers 100, 102 counter-rotate. As shown in the exploded view of the diagram, the fluid 106 pools at an upstream side of the nip 104 and moves through the nip 104 as the rollers rotate.

On a downstream side 108 of the nip 104, the fluid stretches between the surfaces of the two rollers 100, 102 into a fluid filament 110. As the rollers 100, 102 counter-rotate, the surfaces of the rollers 100, 102 to which the fluid filament 110 adheres remains the same, but the space between such surface is greater. The fluid filament 112 grows longer and thinner as the surfaces of the rollers 100, 102 rotate away from each other. When the fluid filament 112 reaches a point of the liquid bridge it becomes unstable at this point, this is also the capillary break-up point for the fluid filament 112. The fluid filament 112 breaks up into several droplets 114 and leaves excess fluid 116 behind on each of the roller's surface. The excess fluid 116 retracts to the surface of its respective roller and can be part of the fluid that pools and moves through the nip on the next rotation of the rollers. The process can be repeated to provide a continuous mist.

To effect better spreading of high surface tension fluids, the surface of the rollers is geometrically inhomogeneous. These inhomogeneous patterns can consist of regular geometric shape patterns, some examples include but not limited to helical grooves, circular grooves, dimples of various shapes or cross hatch patterns. As the term is used here, a helical groove is one continuous groove that spirals around the roller. This is in contrast with a series of individual circular grooves, that are all self-contained circles.

It is manufactured typically by turning the roller while a tool of some kind presses into the roller and traverses it while it spins. There are several other manufacturing methods to fabricate inhomogeneous geometric patterns on roller surfaces which are all applicable to control the spreading of high surface tension fluids and tailoring the fluid filament size, thereby the mist characteristics. These methods include providing a cylindrical core of a hydrophilic material, covering the cylindrical core with a hydrophobic surface, and creating grooves in the hydrophobic surface to form a geometrically inhomogeneous pattern of the hydrophilic material.

Covering the cylindrical core with a hydrophobic surface may result from one of many processes. In one embodiment, including casting the hydrophobic material over the hydrophilic core, then hardening the hydrophobic material. In another embodiment, coating the hydrophobic surface comprises spray coating the hydrophilic core prior to creating the grooves. The process may also involve plasma treating the hydrophilic core and applying a silylating agent to the surface. In another embodiment, a polymer is bound to the surface through chemical linkage, which may be covalent, ionic, dative or through chelation, to form brushes or chains. This would allow selection of a monomer to achieve a desired balance between the hydrophobic and hydrophilic properties.

Forming the grooves may also be accomplished in one of several ways. These include turning the hydrophobic surface on a lathe, sand blasting the hydrophobic surface, and etching, either chemically or with a laser, the hydrophobic surface.

In an alternative embodiment, the process may occur in a reverse manner. A hydrophobic core is first machined, sand-blasted, or laser etched to a selected texture. The surface is functionalized to make it hydrophilic. The small fraction of the top layer, or ridges, is removed in order to expose the original hydrophobic surface, leaving the hydrophilic grooves untouched.

FIG. 3 shows an embodiment of two counter rotating rollers. The top roller 102 has a smooth surface and the bottom roller 100 has a patterned surface. In this embodiment, the pattern is a helical groove at 108 threads per inch (TPI). As the fluid is picked up by either roller, it spreads over the patterned roller in a more uniform layer, even with higher surface tension fluids. This allows for more reproducible filament and therefore droplet formation.

In one embodiment, the roller is formed by taking a hydrophilic core and covering it with a hydrophobic material. The hydrophobic material is then cut away by machining, leaving hydrophilic grooves surrounded by hydrophobic ridges. FIG. 4 shows an example of such a roller. The roller 100 has hydrophilic grooves such as 206 and hydrophobic ridges 204. One approach may involve a hydrophobic coating on the ridges to ensure retaining the high surface tension fluid in the grooves.

FIGS. 5-7 show different embodiments of the patterning on the surface of the roller. FIG. 5 shows a helically grooved roller having 108 TPI. FIG. 6 shows a roller having a helically grooved roller having 64 turns per inch. FIG. 7 shows a roller with a different pattern. In this embodiment, the surface of the roller has a cross hatching pattern.

A helical groove has several different parameters, including the turn radius, the turns per inch of the helix, and the other dimensions of the groove, such the width and the depth. The embodiments here set out 108 TPI, 64 TPI, grooves of 127 micrometer width, and rollers with turn radii of 12.5 and 6.3 micrometers. These provide specific examples, and should not be construed to limit the applicability of the claims to other dimensions or parameters. FIGS. 8 and 9 show surface profiles for a 64 TPI roller and a 108 TPI roller. The roller has 127 micrometer wide grooves running the axis of the roller.

In this manner, higher surface tension fluids can be converted to a spray of droplets using a filament extension atomizer system. The grooved roller allows for better spreading of the fluid over one of a pair of counter rotating rollers. The control of the dimensions of the geometric inhomogeneous patterns, such as the depth and width of the grooves noted as examples above, can also provide better control over the size of the filaments, which in turn provides better control of the size of the droplets.

It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

Claims

1. A roller, comprising:

a cylindrical outer surface of a hydrophobic material;
an inner core of a hydrophilic material within the outer surface; and
a geometric pattern of grooves in the outer surface that expose portions of the inner core of the hydrophilic material to allow the portions to accept fluid.

2. The roller of claim 1, wherein the hydrophilic material comprises polyetherimide.

3. The roller of claim 1, wherein a size of ridges between the grooves is less than three times a size of the grooves.

4. The roller of claim 1, wherein the hydrophobic material comprises polytetrafluoroethylene.

5. The roller of claim 1, wherein the geometric pattern is a helical groove and has a turned finish having a radius based upon a filament size.

6. The roller of claim 1, wherein the grooves have dimensions that result in a capillary pressure of less than −100 Pascals for a selected liquid.

7. A method of manufacturing a roller, comprising:

providing a cylindrical core of a hydrophilic material;
covering the cylindrical core with a hydrophobic surface;
creating grooves in the hydrophobic surface to expose the hydrophilic material in a geometrical pattern to allow the grooves to accept fluid.

8. The method of claim 7, wherein covering the cylindrical core with a hydrophobic surface comprises inserting the hydrophilic core inside a hydrophobic cylindrical surface.

9. The method of claim 7, wherein covering the cylindrical core with a hydrophobic surface includes casting the hydrophobic material over the hydrophilic core, then hardening the hydrophobic material.

10. The method of claim 7, wherein creating the hydrophobic surface comprises spray coating the hydrophilic core with a hydrophobic material prior to creating grooves.

11. The method of claim 7, wherein creating grooves comprises one of turning the hydrophobic surface on a lathe, sand blasting the hydrophobic surface, laser ablation, and etching the surface.

12. The method of claim 7, wherein covering the cylindrical core with a hydrophobic surface comprises casting the hydrophobic surface over the cylindrical core.

13. The method of claim 7, wherein covering the cylindrical core with a hydrophobic surface comprises plasma treating the hydrophilic core and applying a silylating agent to the hydrophobic surface prior to creating the grooves.

14. The method of claim 7, wherein covering the cylindrical core with a hydrophobic surface comprises grafting polymer chains or brushes onto the hydrophobic surface prior to creating the grooves.

15. The method of claim 14, wherein grafting the polymer chains on the hydrophobic surface comprises selecting monomers to achieve a desired balance of hydrophobic and hydrophilic properties.

16. A method of manufacturing a roller, comprising:

forming a geometric pattern of grooves on a surface of a hydrophobic core;
making the surface of the hydrophobic core hydrophilic; and
removing a portion of the surface of the hydrophobic core to expose the hydrophobic core, leaving hydrophilic grooves to allow the hydrophilic grooves to accept fluid.

17. The method of 16, wherein forming the pattern of grooves comprises one of machining, sand blasting, chemically etching or laser etching the hydrophobic core.

Referenced Cited
U.S. Patent Documents
2291046 July 1942 Lange
3406660 October 1968 Simm
3554815 January 1971 Otto
3626833 December 1971 Koch
3649829 March 1972 Randolph
2296861 September 1972 Albert
3702258 November 1972 Gibbons et al.
3717875 February 1973 Arciprete et al.
3873025 March 1975 Qvarnstrom
3926114 December 1975 Matuschke
3988986 November 2, 1976 Zimmer
4011993 March 15, 1977 Mizuno et al.
4034670 July 12, 1977 Zavodny
4046931 September 6, 1977 Innes et al.
4222059 September 9, 1980 Crean et al.
4332281 June 1, 1982 Baba
4384296 May 17, 1983 Torpey
4860652 August 29, 1989 Kawata
4993320 February 19, 1991 Kochsmeier
5022948 June 11, 1991 Hallworth
5123350 June 23, 1992 Fadner
5127325 July 7, 1992 Fadner
5191703 March 9, 1993 John
5207158 May 4, 1993 Fadner
5216952 June 8, 1993 Hoff et al.
5270086 December 14, 1993 Hamlin
5314119 May 24, 1994 Watt
5326598 July 5, 1994 Seaver et al.
5332472 July 26, 1994 Cutright et al.
5835114 November 10, 1998 Nagata et al.
6033513 March 7, 2000 Nakamura
6125756 October 3, 2000 Nussel et al.
6382524 May 7, 2002 James
6576861 June 10, 2003 Sampath et al.
6622335 September 23, 2003 Anderson et al.
6934142 August 23, 2005 Grosse et al.
7083830 August 1, 2006 Minko
RE40722 June 9, 2009 Chappa
7837307 November 23, 2010 Schmitt
8132744 March 13, 2012 King et al.
8272579 September 25, 2012 King et al.
8273286 September 25, 2012 Fram
8511251 August 20, 2013 Sato
8522711 September 3, 2013 McNeil et al.
8523340 September 3, 2013 Sabo et al.
8552299 October 8, 2013 Rogers et al.
8720370 May 13, 2014 Rebstock
8742246 June 3, 2014 Toyoda et al.
9021948 May 5, 2015 Pattekar
20010011511 August 9, 2001 Kawabata et al.
20020053320 May 9, 2002 Duthaler et al.
20030183099 October 2, 2003 De Vroome
20030222950 December 4, 2003 Jeanmaire
20040020382 February 5, 2004 McLean et al.
20040079282 April 29, 2004 Sano et al.
20040217184 November 4, 2004 Seidel
20050000231 January 6, 2005 Lee
20050250900 November 10, 2005 Stofko
20060035033 February 16, 2006 Tanahashi et al.
20060071978 April 6, 2006 Steiner et al.
20090011212 January 8, 2009 Dubey
20090014046 January 15, 2009 Yu et al.
20090032492 February 5, 2009 Kunze-Concewitz
20090153627 June 18, 2009 Barbet
20100064917 March 18, 2010 Blanchard et al.
20100154856 June 24, 2010 Yuichi et al.
20110011289 January 20, 2011 Bohm et al.
20110017431 January 27, 2011 Yang et al.
20110031100 February 10, 2011 Qtaishat
20110150036 June 23, 2011 Lee et al.
20110154558 June 30, 2011 Peter et al.
20110220147 September 15, 2011 Schreiber et al.
20120103213 May 3, 2012 Stowe et al.
20120145019 June 14, 2012 Cheng et al.
20120145021 June 14, 2012 Pfeil
20120227778 September 13, 2012 Leonov
20130070031 March 21, 2013 Nelson
20130087180 April 11, 2013 Stark et al.
20140015901 January 16, 2014 Marcus
20140146116 May 29, 2014 Paschkewitz
20150115057 April 30, 2015 Beck et al.
20150119477 April 30, 2015 Beck et al.
20150343407 December 3, 2015 Johnson et al.
20150343468 December 3, 2015 Johnson et al.
20150343477 December 3, 2015 Johnson et al.
20170203504 July 20, 2017 Johnson et al.
Foreign Patent Documents
2227834 August 2011 EP
Other references
  • Bhat, Pradeep P., “Formation of beads-on-a-string structures during break-up of viscoelastic filaments,” Aug. 2010, vol. 6:625-631, Nature Physics, 7 pages.
  • Le, Hue P., “Progress and Trends in Ink-jet Printing Technology,” Jan./Feb. 1998, vol. 42:49-62, Journal of Imaging Science and Technology, 16 pages, found at: http://www.imaging.org/ist/resources/tutorials/inkjet.cfm.
  • Oliveira, Monica S., “Iterated Stretching, Extensional Rheology and Formation of Beads-on-a-String Structures in Polymer Solutions,” Jan. 20, 2006, Special Issue of JNNFM on Extensional Flow, MIT, Cambridge, MA, 36 pages.
  • Owen, M., “Misting of non-Newtonian Liquids in Forward Roll Coating,” Jul. 13, 2011, Journal of Non-Newtonian Fluid Mechanics, vol. 166:1123-1128, 6 pages.
  • Shi, X.D., “A Cascade of Structure in a Drop Falling from a Faucet,” Jul. 8, 2004, vol. 265:219-222, Science, 4 pages.
  • Chapter 15, “Ink Jet Printing”, 14 pages, found at http://www.lintech.org/comp-per/15INK.pdf.
  • Marple, A. and Liu, Y.H.: “Characteristics of Laminar Jet Impactors”, Environmental Science & Technology, vol. 8, No. 7, Jul. 1974, pp. 648-654.
  • Bailey, Adrian G.: “The Science and technology of electrostatic powder spraying, transport and coating”, Journal of Electrostatics, vol. 45, 1998, pp. 85-120.
  • Domnick, et al.: “The Simulation of Electrostatic Spray Painting Process with High-Speed Rotary Bell Atomizers. Part II: External Charging”, Part. Part. Syst. Charact. vol. 23, 2006, pp. 408-416, URL: http://www.ppsc-journal.com.
  • Kelly, Ryan T, et al.: “The ion funnel: theory, implementations, and applications”, Mass Spectrometry Reviews,vol. 29, 2010, pp. 294-312.
  • Crowe, Clayton et al.: “Multiphase Flows With Droplets and Particles”, CRC Press, LLC, 1998.
  • McClure, Max, “Stanford Researchers' Cooling Glove Better than Steroids—and Helps Solve Physiological Mystery Too”, Stanford Report, Aug. 29, 2012, 3 pages, retrieved from the Internet: http://news.stanford.edu/news/2012/august/cooling-glove-research-082912.html, retrieved on Dec. 19, 2014.
  • Matheson, Rob, “Cool Invention Wins First Place at MADMEC”, MIT News Office, Oct. 17, 2013, 3 pages, retrieved from the Internet: http://newsoffice.mit.edu/2013/madmec-design-competition-1017, retrieved on Dec. 19, 2014.
  • Vanhemert, Kyle, “MIT Wristband Could Make AC Obsolete”, Wired.com, Oct. 30, 2013, retrieved from the Internet: http://www.wired.com/2013/10/an-ingenious-wristband-that-keeps-your-body-at-theperfect-temperature-no-ac-required/, retrieved on Dec. 19, 2014.
  • Francioso, L., “Flexible thermoelectric generator for ambient assisted living wearable biometric sensors”, Journal of Power Sources, vol. 196, Issue 6, Mar. 15, 2011, pp. 3239-3243.
  • http://www.stacoolvest.com/, retrieved on Dec. 19, 2014.
  • http://www.steelevest.com/, retrieved on Dec. 19, 2014.
  • http://veskimo.com/, retrieved on Dec. 19, 2014.
  • http://glaciertek.com/, retrieved on Dec. 19, 2014.
  • Chen, A., “Dispenser-printed planar thick-film thermoelectric energy generators,” J. Micromech. Microeng., 21(10), 2011.
  • Hewitt, A.B., “Multilayered Carbon Nanotube/Polymer Composite Based Thermoelectric Fabrics,” Nano Letters, 12(3), pp. 1307-1310, 2012.
  • Arens, E., “Partial- and whole-body thermal sensation and comfort—Part I: Uniform environmental conditions,” Journal of Thermal Biology, vol. 31, Issues 1-2, Jan. 2006, pp. 53-59.
  • Arens, E., “Partial- and whole-body thermal sensation and comfort—Part II: Non-uniform environmental conditions,” Journal of Thermal Biology, vol. 31, Issues 1-2, Jan. 2006, pp. 60-66.
  • Bullis, Kevin, “Expandable Silicon”, MIT Technology Review, Dec. 14, 2007, URL: http://www.technologyreview.com/news/409198/expandable-silicon/, retrieved from the Internet on Dec. 23, 2014.
  • “Ortho-Planar Spring”, BYI Mechanical Engineering Website, URL: http://compliantmechanisms.byu.edu/content/ortho-planar-spring, retrieved from the Internet on Dec. 23, 2014.
  • S.-J. Kim, J.-H. Wea and B.-J. Cho: “A wearable thermoelectric generator fabricated on a glass fabric,” Energy Environmental Science, 2014.
  • L. Francioso, C. De Pascali, A. Taurino, P. Siciliano, A. De Risi: “Wearable and flexible thermoelectric generator with enhanced package,” In Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI, 876306, May 2013.
  • C. Huizenga, H. Zhang, E. Arens, D. Wang: “Skin and core temperature response to partial-and whole-body heating and cooling,” Journal of Thermal Biology, vol. 29, Issues 7-8, Oct.-Dec. 2004, pp. 549-558.
  • Sholin, V. et al.: “High Work Function Materials for Source/Drain Contacts in Printed Polymer Thin Transistors,” Applied Physics Letters, vol. 92, 2008.
  • Zhou, Li, et al.: “Highly Conductive, Flexible, Polyurethane-Based Adhesives for Flexible and Printed Electronics,” Advanced Functional Materials, vol. 23, p. 1459-1465, wileyonlinelibrary.com.
Patent History
Patent number: 10464094
Type: Grant
Filed: Jul 31, 2017
Date of Patent: Nov 5, 2019
Patent Publication Number: 20190030559
Assignee: PALO ALTO RESEARCH CENTER INCORPORATED (Palo Alto, CA)
Inventors: Ravi Neelakantan (Redwood City, CA), Elif Karatay (Mountain View, CA)
Primary Examiner: Jason L Vaughan
Application Number: 15/665,048
Classifications
Current U.S. Class: Roller (101/348)
International Classification: B05B 17/04 (20060101); B05B 9/03 (20060101); B05B 1/02 (20060101); B29D 99/00 (20100101); B05B 3/02 (20060101); B29K 79/00 (20060101);